Labeling is one of the more complex areas of food law, full of statutes, regulations, exemptions, and exceptions. In 1990, Congress updated food labeling law with the Nutrition Labeling and Education Act, which gave the Food and Drug Administration authority to require specific types of nutrition labels on most food products. The handy Nutrition Facts panel you see on foods today displaying calorie, carbohydrate, fat, protein, and other nutrient amounts is the result of FDA implementing this law.

Originally, trans fats were not on the list of nutrients required to be labeled. In 2003, prompted by health concerns over the increased risk of coronary heart disease linked to lab-created partially hydrogenated oils, FDA issued a rule adding trans fats to the list of items required on food labels. (The rule was finalized in 2006.)

But, here’s where thing get a little tricky. FDA regulations also contain an exception for what the agency calls “insignificant amounts” that are “dietetically trivial and physiologically inconsequential.” This allows manufacturers to fudge the numbers. That’s why food manufacturers will often display “0 grams” when the food contains an “insignificant amount” of that ingredient. Exactly what FDA deems “insignificant” varies. (Here’s a chart in an FDA guidance document that breaks it down.)

Specifically, for all fats (trans, saturated, and unsaturated), the threshold is 0.5 grams per serving. So, if a food contains less than half a gram of trans fat per serving, the nutrition label will almost always say “0 grams” next to trans fat. This is how we get inconsistent food label that lists “0 grams” trans fat on the Nutrition Facts panel (or even worse, call-outs on the front of the package like on this fake butter from Land O Lakes) when the product is actually made with partially hydrogenated oils, which contain trans fat.

I asked registered dietitian Andy Bellatti if this is really such a big deal. Yes, he says, because it’s easy to “rack up one or two grams of trans fat in a day in a few servings. It may not sound like much, but research shows that tiny amounts inflict severe cardiovascular damage.” Yikes. Thanks a lot, FDA.

So don’t fall for the “0 grams trans fat” trick. Just skip the front-of-the-box hype and check the nutrition label plus the ingredient list on the back to see what’s really lurking inside. And always try to minimize your intake of processed food.

Thanks to Neil Thapar for research and drafting assistance for Ask a Food Lawyer. Got a question? Email me: Michele@EatDrinkPolitics.com. (Sorry, but I can’t answer all questions.)